Lifting jack



June 15 1926.

A. c. HOPKINS LIFTING JACK Filed June 28 \\\\\I|IIIIIIII 8 5 w w WWJMM m m a A GWM Patented June 15, 1926.

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ARTHUR C. HOPKINS, OF NILES, MICHIGAN, ASSIGNOR TC NATIONAL STANDARD COM- PANY, N'ILES, MICHIGAN.

LIFIING: JACK.

Application filed June 28, 1924. semi No. 722,938.

This invention relates to improvements in lifting acks.

The main objects of this invention are to provide an improved lifting jack which has a relatively long range or throw and at the same time 18 very compact.

A further object is to provide a lifting jack having these advantages which is economical in structure.

Objects relating to details and economies of construction and operation will definitely appear from the detailed description to follow. 2

I accomplish the objects of my invention by the devices and means described in the following specification. The clearly defined and pointed out in the claims.

A structure which is a preferred embodiment of my invention is clearly illustrated in the accompanying drawing, forming a part of this application, in which:

Fig. I is a fragmentary elevation of a lifting jack embodying the features of my invention, the standard being fully extended.

Fig. II is a side elevation of a jack in collapsed position, the driving shaft or crank being partially broken away.

Fig. III is a fragmentary vertical central section through the driving means.

In the drawing similar reference characters refer to similar parts throughout the several views.

Referring to the drawing, my improved lifting jack comprises a plurality of sections 1, 2 and 3, section 1 being the base section,

section 2 the intermediate section and section 3 the top section. Sections 1 and 2 are tubular and internally threaded. Section 2 has an enlarged nut portion l coacting with the threads 5 of the bottom or base section. Section 3 has a nut portionfi coacting with the threads 7 of the intermediate section.

The threads 5 and 7 are of different pitch so that when the top section 3 is rotated it is first extended, its nut portion 6 engaging the shoulder stop 8 at the top of section 2 causes the section 2 to rotate whereby it is.

extended until its nut portion 4 engages the stop 9 at the upper end of the section 1. The bottom and intermediate sections have unthreaded inwardly projecting flange-like portions at their upper ends which coact with the sections arranged therethrough to laterally support the same. In ractice these parts are not a close bearing t; some invention is as'the part, such as a vehicle axle, is tilted in raising the same. These unthreaded portions, however, do serve as hearing members limiting this lateral swing and relieving the threads of strain and preventing an undue camming or binding action thereon.

By attaching the shaft 12 as is described it servesas a means for locating the jack and for preventing the head from rotating prior to its engagement with the axle or part to be lifted.

The top section is provided with a head 10 having a laterally projecting angled arm 11 carrying the driving or crank shaft 12 which is provided with a crank 13 at its outer end. On the inner end of this shaft 12 is a beveled gear 14 meshing with the gear 15 secured. to the standard section 3.

My improved jack is very compact when collapsed. and at the same time has a relatively long stroke, thereby especially adapt- 111g it for vehicles equipped with balloon tires or where a long throw or stroke is required.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In a lifting jack, the combination of an internally threaded standard with an unthreaded bearing portion at its upper end, an internally threaded intermediate section having an nnthreaded inwardly projecting flange at its upper end and an external threaded portion at its lower end coacting with the threads of said lower section, a top section having a threaded portion at its lower end coacting with the internal threads of said intermediate portion, the unthreaded flanges of said bottom and intermediate sections constituting lateral supports for the parts disposed therethrough, a head swiveled upon the top section and provided with a laterally projecting arm, a driving shaft carried by said arm, and coacting gears on said driving shaft and said top section, said driving shaft constituting means for positioning and supporting said head against rotation.

2. Ina lifting jack, the combination of a standard comprising a plurality of telescoping sections, the lower and intermediate sections being tubular and threaded and having unthreadeol portions at internally their upper ends, the top and intermediate sections having external threads coacting with the internal threads of said intermediate and bottom sections, respectively, the unthreaded portions of said bottom and intermediate sections constituting lateral supports for the sections arranged therethrough, a head swiveled upon the top section and provided with a laterally projecting arm, a driving shatt carried by said arm, and coacting gears on said driving shaft and said top section, said driving shaft constituting means for positioning and supporting said head against rotation.

3. In a lifting jack, the combination oil? a standard comprising a plin'ality ot telescoping sections, the lower and intermediate sections being tubular and internally threaded and having unthread-ed portions at their upper ends, the top and intermediate sections having external tl'n'eads coacting with the internal threads of said intermediate and bottom sections, respectively, the nnthreaded portions of said bottom and intermediate sections constituting lateral supports for the sections arranged there through, and means for rotating the top section.

4. In a lifting jack, the combination of a standard comprising a plurality of telescoping sections having threaded engagement, the pitch of the threads being varied so that the sections are successively extended upon rotation of the top section, a sn'iveled head upon the top section and provided with a laterally projecting arm. a driving shat't carried by said arm, and coacting gears on said driving shaft and said top section, said driving shaft constituting means for positioning and supporting said head against rotation.

In Witness whereof I have hereunto set my hand.

ARTHUR C. HOPKINS. 

